1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990, 1993, 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Mike Olson. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35 #if defined(LIBC_SCCS) && !defined(lint) 36 static char sccsid[] = "@(#)bt_put.c 8.8 (Berkeley) 7/26/94"; 37 #endif /* LIBC_SCCS and not lint */ 38 #include <sys/types.h> 39 40 #include <errno.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 45 #include <db.h> 46 #include "btree.h" 47 48 static EPG *bt_fast(BTREE *, const DBT *, const DBT *, int *); 49 50 /* 51 * __BT_PUT -- Add a btree item to the tree. 52 * 53 * Parameters: 54 * dbp: pointer to access method 55 * key: key 56 * data: data 57 * flag: R_NOOVERWRITE, R_SETCURSOR, R_CURSOR 58 * 59 * Returns: 60 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is already in the 61 * tree and R_NOOVERWRITE specified. 62 */ 63 int 64 __bt_put(const DB *dbp, DBT *key, const DBT *data, u_int flags) 65 { 66 BTREE *t; 67 DBT tkey, tdata; 68 EPG *e; 69 PAGE *h; 70 indx_t idx, nxtindex; 71 pgno_t pg; 72 u_int32_t nbytes, tmp; 73 int dflags, exact, status; 74 char *dest, db[NOVFLSIZE], kb[NOVFLSIZE]; 75 76 t = dbp->internal; 77 78 /* Toss any page pinned across calls. */ 79 if (t->bt_pinned != NULL) { 80 mpool_put(t->bt_mp, t->bt_pinned, 0); 81 t->bt_pinned = NULL; 82 } 83 84 /* Check for change to a read-only tree. */ 85 if (F_ISSET(t, B_RDONLY)) { 86 errno = EPERM; 87 return (RET_ERROR); 88 } 89 90 switch (flags) { 91 case 0: 92 case R_NOOVERWRITE: 93 case R_SETCURSOR: 94 break; 95 case R_CURSOR: 96 /* 97 * If flags is R_CURSOR, put the cursor. Must already 98 * have started a scan and not have already deleted it. 99 */ 100 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 101 !F_ISSET(&t->bt_cursor, 102 CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE)) 103 break; 104 /* FALLTHROUGH */ 105 default: 106 errno = EINVAL; 107 return (RET_ERROR); 108 } 109 110 /* 111 * If the key/data pair won't fit on a page, store it on overflow 112 * pages. Only put the key on the overflow page if the pair are 113 * still too big after moving the data to an overflow page. 114 * 115 * XXX 116 * If the insert fails later on, the overflow pages aren't recovered. 117 */ 118 dflags = 0; 119 if (key->size + data->size > t->bt_ovflsize) { 120 if (key->size > t->bt_ovflsize) { 121 storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR) 122 return (RET_ERROR); 123 tkey.data = kb; 124 tkey.size = NOVFLSIZE; 125 memmove(kb, &pg, sizeof(pgno_t)); 126 tmp = key->size; 127 memmove(kb + sizeof(pgno_t), 128 &tmp, sizeof(u_int32_t)); 129 dflags |= P_BIGKEY; 130 key = &tkey; 131 } 132 if (key->size + data->size > t->bt_ovflsize) { 133 if (__ovfl_put(t, data, &pg) == RET_ERROR) 134 return (RET_ERROR); 135 tdata.data = db; 136 tdata.size = NOVFLSIZE; 137 memmove(db, &pg, sizeof(pgno_t)); 138 tmp = data->size; 139 memmove(db + sizeof(pgno_t), 140 &tmp, sizeof(u_int32_t)); 141 dflags |= P_BIGDATA; 142 data = &tdata; 143 } 144 if (key->size + data->size > t->bt_ovflsize) 145 goto storekey; 146 } 147 148 /* Replace the cursor. */ 149 if (flags == R_CURSOR) { 150 if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL) 151 return (RET_ERROR); 152 idx = t->bt_cursor.pg.index; 153 goto delete; 154 } 155 156 /* 157 * Find the key to delete, or, the location at which to insert. 158 * Bt_fast and __bt_search both pin the returned page. 159 */ 160 if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL) 161 if ((e = __bt_search(t, key, &exact)) == NULL) 162 return (RET_ERROR); 163 h = e->page; 164 idx = e->index; 165 166 /* 167 * Add the key/data pair to the tree. If an identical key is already 168 * in the tree, and R_NOOVERWRITE is set, an error is returned. If 169 * R_NOOVERWRITE is not set, the key is either added (if duplicates are 170 * permitted) or an error is returned. 171 */ 172 switch (flags) { 173 case R_NOOVERWRITE: 174 if (!exact) 175 break; 176 mpool_put(t->bt_mp, h, 0); 177 return (RET_SPECIAL); 178 default: 179 if (!exact || !F_ISSET(t, B_NODUPS)) 180 break; 181 /* 182 * !!! 183 * Note, the delete may empty the page, so we need to put a 184 * new entry into the page immediately. 185 */ 186 delete: if (__bt_dleaf(t, key, h, idx) == RET_ERROR) { 187 mpool_put(t->bt_mp, h, 0); 188 return (RET_ERROR); 189 } 190 break; 191 } 192 193 /* 194 * If not enough room, or the user has put a ceiling on the number of 195 * keys permitted in the page, split the page. The split code will 196 * insert the key and data and unpin the current page. If inserting 197 * into the offset array, shift the pointers up. 198 */ 199 nbytes = NBLEAFDBT(key->size, data->size); 200 if ((u_int32_t)(h->upper - h->lower) < nbytes + sizeof(indx_t)) { 201 if ((status = __bt_split(t, h, key, 202 data, dflags, nbytes, idx)) != RET_SUCCESS) 203 return (status); 204 goto success; 205 } 206 207 if (idx < (nxtindex = NEXTINDEX(h))) 208 memmove(h->linp + idx + 1, h->linp + idx, 209 (nxtindex - idx) * sizeof(indx_t)); 210 h->lower += sizeof(indx_t); 211 212 h->linp[idx] = h->upper -= nbytes; 213 dest = (char *)h + h->upper; 214 WR_BLEAF(dest, key, data, dflags); 215 216 /* If the cursor is on this page, adjust it as necessary. */ 217 if (F_ISSET(&t->bt_cursor, CURS_INIT) && 218 !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) && 219 t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= idx) 220 ++t->bt_cursor.pg.index; 221 222 if (t->bt_order == NOT) { 223 if (h->nextpg == P_INVALID) { 224 if (idx == NEXTINDEX(h) - 1) { 225 t->bt_order = FORWARD; 226 t->bt_last.index = idx; 227 t->bt_last.pgno = h->pgno; 228 } 229 } else if (h->prevpg == P_INVALID) { 230 if (idx == 0) { 231 t->bt_order = BACK; 232 t->bt_last.index = 0; 233 t->bt_last.pgno = h->pgno; 234 } 235 } 236 } 237 238 mpool_put(t->bt_mp, h, MPOOL_DIRTY); 239 240 success: 241 if (flags == R_SETCURSOR) 242 __bt_setcur(t, e->page->pgno, e->index); 243 244 F_SET(t, B_MODIFIED); 245 return (RET_SUCCESS); 246 } 247 248 #ifdef STATISTICS 249 u_long bt_cache_hit, bt_cache_miss; 250 #endif 251 252 /* 253 * BT_FAST -- Do a quick check for sorted data. 254 * 255 * Parameters: 256 * t: tree 257 * key: key to insert 258 * 259 * Returns: 260 * EPG for new record or NULL if not found. 261 */ 262 static EPG * 263 bt_fast(BTREE *t, const DBT *key, const DBT *data, int *exactp) 264 { 265 PAGE *h; 266 u_int32_t nbytes; 267 int cmp; 268 269 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) { 270 t->bt_order = NOT; 271 return (NULL); 272 } 273 t->bt_cur.page = h; 274 t->bt_cur.index = t->bt_last.index; 275 276 /* 277 * If won't fit in this page or have too many keys in this page, 278 * have to search to get split stack. 279 */ 280 nbytes = NBLEAFDBT(key->size, data->size); 281 if ((u_int32_t)(h->upper - h->lower) < nbytes + sizeof(indx_t)) 282 goto miss; 283 284 if (t->bt_order == FORWARD) { 285 if (t->bt_cur.page->nextpg != P_INVALID) 286 goto miss; 287 if (t->bt_cur.index != NEXTINDEX(h) - 1) 288 goto miss; 289 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0) 290 goto miss; 291 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index; 292 } else { 293 if (t->bt_cur.page->prevpg != P_INVALID) 294 goto miss; 295 if (t->bt_cur.index != 0) 296 goto miss; 297 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0) 298 goto miss; 299 t->bt_last.index = 0; 300 } 301 *exactp = cmp == 0; 302 #ifdef STATISTICS 303 ++bt_cache_hit; 304 #endif 305 return (&t->bt_cur); 306 307 miss: 308 #ifdef STATISTICS 309 ++bt_cache_miss; 310 #endif 311 t->bt_order = NOT; 312 mpool_put(t->bt_mp, h, 0); 313 return (NULL); 314 } 315